Flexible panel form for thin shells



Dec. 21, 1965 P. GRAHAM 3,224,726

FLEXIBLE PANEL FORM FOR THIN SHELLS Filed Dec. 15, 1964 5 1 i? 307 '35,;5 6 5 i "w'."" 1i F 4b M INVENTOR. Phi/lip Graham RNEY United StatesPatent ()fitice 3,224,726 Patented Dec. 21, 1965 3,224,726 FLEXIBLEPANEL FORM F OR THIN SHELLS Phillip Graham, 2825 Glenrnore Ave.,Pittsburgh, Pa. Filed Dec. 15, 1964, Ser. No. 418,494 9 Claims. (Cl.249207) This invention relates to improvements in flexible form formolding thin shell building panels, including adjustable flexibleelastic edge forms which can be used to cast curved and flat, thinshell, reinforced panel sections of cementitious materials and plastics,which panel sections can be readily interlocked or bonded together toobtain an integral buildingshell of great strength. This invention is ac-ontinuation-in-part of my copending application Serial No. 86,814, nowPatent No. 3,161,938, filed February 2, 1961, entitled Flexible PanelForm for Thin Shells. Applicant also claims rights to an earlier filingdate to common subject matter that is describe-d in the presentapplication, which was also described in his application Serial No.785,273, filed January 6, 1959, now Patent No. 2,971,237, entitledFlexible Building Panel Form. The copending application Serial No.86,814 was a continuation-in-part of application Serial No. 785,273.

This invention particularly refers to adjustable forming means that hasdurable elastic flexible edge forms that allow low cost, quick andaccurate molding of various shapes and sizes of curved and flat,precast, prestressed, reinforced thin shell concrete panel sections.

My Patent No. 3,154,888, entitled Building Construction, and my PatentNo. 2,971,237, describe'how panels formed with such flexible forms canbe used to build shelters; in addition, these patents list my numerousrelated patents that supplement the flexible form means in buildingshelters.

The form means allows multiple curved thin shell, precast panels to bemolded accurately at low cost. The form means allows accuratepositioning of fastening means along the edges of the-panels so thepanels can be quickly and securely joined at erection. This fasteningmeans allows precast sections to be erected dry with pins duringinclement weathergrout mortar being inserted in the joints at a latersuitable period. Non-elastic panel portions of the form means can bemade of concrete; they can be used to mold the curved faces of theprecast building panels, such concrete panel forms may be used asbuilding panels after they have outlived their usefulness as forms.

The form means embodied in this invention is an improvement over theform means described in my Patent No. 3,161,938, since it has simple,low cost, wire supportfastener means that includes a pin portion that isinte grally secured with the remainder of the support-fastener to allowreinforcing strand means to be easily coupled and uncoupled quickly.

An object of my invention is to provide an efficient, low cost, wiresupport-fastener means having a pin portion that is integral with theremainder of the supportfastener means.

Another object of my invention is to provide an efficient curvable,elastic, flexible, plastic edge form strip that is able to accuratelymold the edges of straight and curved, reinforced thin shell precastcementitious sections of various suitable widths, lengths andthicknesses, including tapered thicknesses; furthermore, to provide asimple low cost pin integral with a wire supportfastener means toposition and prestress the reinforcing, also means to quickly andaccurately position connectors that are on the ends of the reinforcing.

Other objects of my invention will become more apparent from thefollowing description taken with the accompanying drawings wherein:

FIG. 1 is a fragmentary plan view showing flexible forms being used tomold a thin reinforced concrete section;

FIG. 2 is an enlarged, fragmentary sectional view taken along line 22 ofFIG. 1;

FIG. 3 is an enlarged, fragmentary elevational View taken along line 33of FIG. 1;

FIG. 4 is an enlarged, fragmentary, sectional View taken along lines 4-4of FIGS. 1 and 3;

FIG. 5 is a fragmentary, sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is a fragmentary, sectional view taken along line 66 of FIG. 3;

FIG. 7 is a fragmentary, sectional view taken along line 77 of FIG. 5;

FIG. 8 is a fragmentary plan view showing details of the spacer strand;

FIG. 9 is a fragmentary view similar to FIG. 4, showing a wiresupport-fastener;

Referring to the drawing, FIGS. 1 to 4 inclusive show assemblies F1 andF2 in an arrangement for molding precast, prestressed, reinforcedconcrete panel sections 1. The assemblies are stacked on the base form2. Additional assemblies may be stacked above the assembly F2. MyPatents No. 3,161,938 and No. 2,971,237 describe such assemblies andtheir use in detail. The assembly F1 would enclose a space before apanel 1 is formed in it. Each of the assemblies F1 and F2 has a flexibleadjustable elastic and resilient plastic or rubber edge form strip 3. Anassembly may be stripped of its form 3 so the panel 1 may be used as abuilding panel. An assembly may also be kept with its form 3 intact withthe panel 1, so the assembly may be used as a form until the panelportion deteriorates from usage or is no longer needed as a form, thenthe panel 1 may be used as a building panel. The stacked casting meansallows the molding of accurate duplications of an intricately curvedpanel surface such that of the base form 2 and apanel 1. A panel 1 foruse as a portion of an additional form assembly may be molded on theform 2. The top surface of the panel 1 may be shaped with a screed orscraper.

When an original curved surface of the base form 2 is made, it may beduplicated in reverse by casting a female form on it, thus obtainingmale and female forms which may be used to mold additional forms orbuilding panels. The lower facing of a panel 1 is usable as a femaleform.

Intricately curved form assemblies with their elastic edging stripssecured to the concrete panel form may be used as seed-like means toreproduce duplicate panel sections at a very low cost as compared toother casting methods.

The casting means shown causes the molding of identical curvatures tothe surfaces of curved panel faces, except that the top surface of thepanel is convex and the bottom surface is concave.

Form assemblies with their panel sections 1 kept intact may be kept instacks so the assemblies are fastened together for safety and ease inhandling as a unit during shipping and storage; furthermore, the forms 3protect the fragile concrete edges and the reinforcing connections frombeing damaged. The form 3 also shields the panel edges from mud, ice,and other objectionable elements.

The base form 2 may be made of concrete, plaster, or other suitablematerials. to it template bar forms 2b and the like. The template barsmay be fastened together to form a frame. The base 2 is anchored to abase plate (not shown), which allows the casting means to be portable.The whole assembly may be suitably tilted, or be mounted vertically,while casting to insure against voids forming in the side surfaces ofthe concrete panels, by diverting air pockets to edges where they can beeliminated or be compensated for with grouting in the field joint.

The base form 2 has anchored.

Template bars 2b and the like may be anchored with bolt inserts 2g. Thetemplate bars 2b and the like have accurately spaced holes that are usedto align and hold the wire support-fasteners 30 of the assembly F1 tothe base 2. The template bars may be omitted if it is preferred tofasten the assembly F1 direct to the base 2, with bolts penetrating thebase to hold the assembly.

The concrete for panel 1 of the assembly F1 can be poured within theconfines of form 3 with the top surface of the panel being leveled witha screed, or the top surface may be molded by placing a completedassembly F2 on top of the assembly F1. When the top surface of a panel 1is to be shaped with a screed, the top portion of the form 3 may bedepressed with a frame formed with template bars.

The form 3 and supplementary metal parts can be positioned to allow themto be used to mold concrete panels of various widths and various lengthsin multiples of eight inches or other suitable modular units, also invarious curvatures as well as fiat shapes; furthermore, the panels canbe molded in various thicknesses with the form 3. The form 3 may becompressed to taper it to allow it to mold a tapered panel. The form 3may be compressed to allow a range of depths for molding panels ofsuitable thicknesses for thin shell building construction. For example,a form 3 with an unrestrained depth of two and a quarter inches that maybe compressed to one and a half inches, would allow its use in molding awide range of panels. Smaller and larger sized forms 3 may be made, suchas smaller sizes for very thin type panels that are to be laminated.

There is accurate modular spacing means for spacing stiff embeddablereinforcing strand rods or wires 4. There are stiff connector means forconnecting the reinforcing strands 4 to the pin portions 30a of thesupport-fasteners 30. A strand 4 has a connector welded to each end, theconnectors being an eyelet or eye connector, like the eye shown in myPatent No. 3,161,938, on one end and a clevis connector 4b on the otherend. The connectors provide a clevis-like pin connected interlockingmeans for joining building panels to each other at erection.

The connection of the strands 4 to the support-fasteners 30 allowstensioning of the reinforcing strands 4. All the ends of the strands 4on one side edge and one end edge of a rectangular panel each have aneye. The ends of strands 4 on the other side edge and the other end edgeof the panel each have a clevis 4b.

A modular unit is used for spacing the reinforcing strands 4 and forsizing of the panel. With this modular system, the reinforcing spacingsare standardized for various types of construction on which it is to beused. Only a half module space is used from the corners of the panel 1and the like to the first uniformly spaced reinforcing strand so thatwhen erected, half module spaces on adjoining panels form a whole modulespace.

The edge form 3 is described fully in my Patents No. 2,971,237 and No.3,161,938. Spaced holes 3g for the reinforcing strands 4 may be punchedthrough the form 3. A slit 3 is cut from each hole 3g to the bottom ofthe form 3. Splicing means for a form assembly is described and shown inmy Patent No. 2,971,237. The form 3 may have longitudinal holes 30, 3d,and 3c. The form 3 may be made of elastic plastic that is stiff enoughso the upper portion of the form will not sag from its own weight. Theform 3 may be made of a more elas tic, weaker plastic that is reinforcedwith fabric or with spring steel wire 3k.

Most of the panel sections to be cast require keying grooves in alltheir edges, so that panels can be keyed together with mortar grout atthe time of erection. The form 3 has a protruding medial portion whichis the groove mold offset 3a.

The form 3 may have a retainer offset 3b, shown in FIGS. 2 and 3, toengage or catch against the spacer wires 5 and thus restrain the form 3from tending to rise due to the lower portion of the form pressuringupwardly. The offset 3b would be particularly useful when the form 3 hasslits 3f; the slits 3f would otherwise broaden and allow the'form 3 torise unhampered by the reinforcing strands 4 and by the spacer strand M.The elastic form 3 may be stretched and compressed to pull it free of asemicured panel 1, spacer strand M, and reinforcing strands 4, withoutdisturbing the pin 30a.

The form 3 with slits 3 and offset 3b may be positioned on strands 4 adistance from the support-fasteners 30, then be slid into the positionshown in FIG. 2, thereby allowing the otfset 3b to be squeezed under thespacer wire 5.

The spacer wires 5 are attached to the splice bars 6 by welding or byother suitable means to form an accurate pliable metal spacing strand M.The spacer strand M is positioned along the full length of the formstrip 3 at substantially the central portion of the form 3. The bars 6are accurately spaced a module apart to match the spacing of the holes3g in the form 3. My Patent No. 3,161,938 describes a spacer strand indetail. Panels of limited accuracy may be molded with forms 3 withoutthe spacer strand M.

Since an eye is thinner than a clevis 4b, an adapter, like the adaptershown in my Patent No. 3,161,938, is slid onto an eye so the eye ispositioned and aligned properly. The clevises 4b and eyes are shouldereddue to the long stems or rectangular rod strand portions 4s beingnarrower than the main portions of the clevises and eyes, the wire 4being welded to the stems. The strands 4s being strong resist forcescaused by rough handling that tends to bend or twist the clevises andeyes out of alignment. The shoulders on the clevises and eyes are forallowing forked wedges to be driven between the cured concrete of thepanel 1 and the main portions of these connectors to tension the strands4.

When a semicured panel 1 is to be allowed to cure for a long period, thespacer strand M and the strip 3 may be pulled free so they may be usedto mold other panels. The elasticity of the form 3 allows the form 3 tobe stretched to permit it to be pulled free of the edging of the panel1.

Pretensioning or so-called prestressing for use with this type of formmeans is described in my Patent No. 3,161,938.

The panels 1 may be made without prestressing the wires 4. Such panelswould be suitable for much construction work, particularly when thepanels are to be used in arch construction.

When curved wires 4, for a curved panel, are positioned above the base 2or above the convex surface of a cured form panel 1, they may besupported by chairs, as described in my Patent No. 3,161,938.

The support-fasteners 30 are used to selectively gauge the effectivedepth of the form 3 and thus the thickness of the panel 1. The fasteners30 restrain the form 3 from tilting. The support fasteners 30 align andsupport the assemblies F2 and the like that are above the assembly F1.The fastener 30 is fastened to the template bar 2b with a bolt 22 and alock washer. A dowel 23 may also be used to position the fastener 30 tothe template bar 2b. The dowel 23 is bolted to the fastener 30. A ridgeon the stem of dowel 23 engages the underside of the fastener 30. Bolts22 may be used to attach and align the fasteners 30 of the assembly F1to the fasteners 30 of the assembly F2. Dowels 23 align the upper andlower fasteners 30. The pointed dowels 23 are selfcentering with theholes in the adjacent form assembly.

A wire support fastener 30 may be made of steel. The wire 30 is formedso as to provide means to perform functions that the more costly supportfastener, described in my Patent No. 3,161,938, can perform. Thesurfaces of the wire 30 that contact each other may be welded together.A pin portion 30a is integral with the fastener 30. The fastener 30 hasa bottom portion 3012 that is engageable with a base 2 or the like. Thefastener 30 may have a top portion 300, which may be like the bottomportion 30b. The bottom 30b and the top 300 may be formed so as toprovide an inner hole 30d and an outer hole 3tle in each portion. Theholes 30d and 30:: may be used to .secure the fastener 30 to a base 2 orthe like, also to like fasteners that may be positioned above and belowit. The pin portion 30a is reinforced by the looped portion 30 that isbent around it. The looped portion 30 also acts as a seat for a clevis4b or the like. The lower crimped portions 30g are an adjusting means tovary the height of the pin portion 300 above the bottom portion 30b. Thecrimps 30g may be squeezed towards each other with a pair of tongs toflatten the bends or crimps to an extent to cause the pin 30a to rise.The crimps 30g may be crimped to a greater degree with another tool towiden them to lower the pin 30a. The upper crimped portions 3012 may besqueezed towards each other to increase the overall height of thefastener 30. The crimps 36g may be crimped to a greater degree to spreadthem wider to decrease the overall height of the fastener 30. Thediagonal arm portions 30k and 36m support the pin portion 30a. The armportions 30k and 30m may be bent with a tool, as shown in FIG. 9, toprovide take-up means to tension the reinforcing 4. The clevis 4b on thereinforcing strand 4 may be forced onto the pin portion i'alla to causethe arms 30k and 30m to be tensioned. The tensioning would stretch theportions 30k and 30m, thus tending to straighten them. The wire used tomake the fastener 30 may be made of steel that is hard enough to givelimited spring action to at least the arms 30k and 30m. The crimpedportions 30g and 3011 and the adjacent portions of the bottom portion30b and the top portion 30c may be nonresilient to allow the bottomportion 30b and the top portion 30c to be gripped with a tool and betwisted to tilt them so they can be made to bear against a warped orcurved base 2 or the like.

A modified fastener (not shown) that is similar to fastener 30 may bemade with pieces of Wire that are welded together and to plates that actas bottom and top portions.

Fasteners 30 allow self-uncoupling of a cured panel 1 from a formassembly F1 and the like. The panel 1 can be attached to a crane and beraised free of the form assembly without any need to manually disengagethe pins from the clevises 4b or eyes. The form assembly P1 with a curedpanel 1 engaged to it may overturned with a crane, causing the panel 1to automatically uncouple itself by falling freely away from itsengagement with the form assembly F1 and its pin means.

Wire mesh fabric may be used for reinforcing rather than wires 4, asdescribed in my Patent No. 3,161,938. Reinforcing rod anchors are weldedto the embeddable strand portions 4s of clevises 4b and eyes. The wirefabric may be stretched and be fastened to the anchors. Fiber glass maybe embedded in the concrete for reinforcing and/ or insulation.

When the form assemblies are used to mold panels that are tapered inthickness, the form assemblies used to mold the top and bottom surfacesof the tapered panel are variably spread apart, the form 3 beingdepressed to a tapered shape. The fasteners 30 would be suitablyadjusted to support the tilted form assemblies to maintain the selectivevariable thicknesses due to the tilting.

The fluid concrete for a panel 1 may be inserted into a form assembly byvarious means. The concrete may be inserted through the access holesthat are cored in the panels 1. Concrete can be deposited within theconfines of the form 3 of an assembly before a complete form assembly isused to cap the fluid concrete. The excess concrete is forced out of theholes 10. The holes 10 may also be used for inserting vibrators. Anaccess 6 unit for inserting concrete through the elastic form means isdescribed in my Patent No. 2,971,237.

In a typical joint of the interlocked panels like panel 1, a pin or boltconnects each eye to a clevis 4b. The panels 1 are keyed together withthe grout mortar.

A panel similar to panel 1 may be molded with only a portion of thepanel edging being molded with elastic form 3. The other portion of thepanel edging may be molded by other suitable form means, including edgesof like panels that are positioned alongside the space for molding apanel, so as to mold the edging.

Thus it will be seen that I have provided economical form means that iscapable of performing a wide variety of operations to suit manyconditions.

While I have illustrated and described several embodiments of myinvention, it will be understood that these are by way of illustrationonly, and that various changes and modifications may be made within thecontemplation of my invention and within the scope of the followingclaims.

I claim:

1. A fastener for a form having an elastic edge for molding a thincementitious panel having embeddable reinforcing strand means; saidfastener consisting of a single metallic wire, said wire having a lowerlooped portion forming a base, said lower looped portion forming atleast one hole for receiving a supporting element, said wire having asubstantially vertical portion and an upper looped portion, said upperlooped portion forming at least one hole, said wire having a portionoffset from said vertical portion, said offset portion including aterminal portion of said wire, said terminal portion forming a pin, saidpin being substantially parallel to said vertical portion, said terminalportion projecting outwardly away from the plane of said base, each ofsaid embeddable reinforcing strand means having an end portion whichincludes an aperture, said pin accurately positioning said strand meansend portion so that said aperture faces towards the planes of the majorsurfaces of said panel, whereby said strand means end portion may bequickly coupled to said pin and whereby said panel may be easily andquickly pulled away from and automatically uncoupled from said fastenerwithout disturbing said pin.

2. A fastener as recited in claim 1, wherein said wire includes lowercrimped means above said lower looped portion, said lower crimped meansbeing pliable so that it may be flattened to an extent to raise said pinand may be bent more acutely to lower said pin, whereby said embeddablereinforcing strand can be variably positioned above said base andwhereby said fastener can be varied in height.

3. A fastener as recited in claim 1, wherein said wire includes uppercrimped means below said upper looped portion, said upper crimped meansbeing pliable so that it may be flattened to an extent to raise saidupper looped portion and may be bent more acutely to lower said upperlooped portion, whereby said fastener may be varied in height whilemaintaining said pin a constant height above said base.

4. A fastener as recited in claim 1, wherein said wire includes apliable portion adjacent to said lower looped portion, whereby saidpliable portion may be bent to cause said lower looped portion toconform to the plane of said supporting element.

5. A fastener as recited in claim 1, wherein said wire having a secondportion offset from said vertical portion, said second offset portionincluding a second terminal portion of said wire, said second terminalportion forming a substantial loop around a lower portion of said pin,thereby restraining said pin from moving objectionably and whereby saidloop acts as a seat for an end portion of said embeddable reinforcingstrand means.

6. A fastener as recited in claim 1, wherein said lower looped portionand said upper looped portion each have two holes, whereby said fastenermay be securely restrained from pivoting laterally.

7. A fastener as recited in claim 2, wherein said wire includes uppercrimped means below said upper looped portion, said upper crimped meansbeing pliable so that it may be flattened to an extent to raise saidupper looped portion and may be bent more acutely to lower said upperlooped portion, whereby said fastener may be varied in height to asubstantial degree.

8. A fastener as recited in claim 7, wherein said wire has a secondportion offset from said vertical portion, said second offset portionincluding a second terminal portion of said wire, said second terminalportion forming a substantial loop around a lower portion of said pin,thereby restraining said pin from moving objectionably and whereby saidloop acts as a seat for an end portion of said embeddable reinforcingstrand.

9. A form for molding at least a portion of a thin cementitious buildingpanel having stiff embeddable metal strand means spaced along at leastthe edging of said building panel portion, said form comprising anelongated elastic strip, a base for supporting said strip, said stripbeing sufiiciently rigid so as to prevent sagging of its top portionwhen supported on said base, said strip having an effective heightsubstantially equal to the thickness of said building panel portion tobe cast, said strip having a length at least sufficient to mold saidedging of said building panel portion, said strip being sufficientlyflexible so as to be bendable in all directions to allow it to followthe contours of curved and fiat planes, said strip confining the freshcementitious aggregate of said building panel portion deposited ontosaid base and defining the shape of said edging, said strip havingspaced transverse holes through an intermediate portion of its heightand substantially parallel to the plane of the said base, saidembeddable metal strand means having end portions extending through saidholes, a plurality of fasteners disposed along the length of said stripfor fastening said strip to said base and for anchoring the said endportions of said embeddable metal strand means, said end portionsincluding connector means, each of said connector means including anaperture, each of said fasteners consisting of a single metallic wire,said wire having a lower looped portion forming a bottom, said lowerlooped portion forming at least one hole for receiving said base, saidwire having a substantially vertical portion and an upper loopedportion, said upper looped portion forming at least one hole, said wirehaving a portion otfset from said vertical position, said offset portionincluding a terminal portion of said wire, said terminal portion forminga pin, said pin beng substantially parallel to said vertical portion,said terminal portion projecting outwardly away from the plane of saidbase, said pins coupling said connector means, wherein said anchoring isprovided, and wherein each of said pins accurately positioning one ofsaid connector means so that said aperture faces towards the planes ofthe major surfaces of said panel, whereby said connector means may bequickly coupled to said pins and whereby said panel may be easily andquickly pulled away from and automatically uncoupled from said fastenerswithout disturbing said pins.

References Cited by the Examiner UNITED STATES PATENTS 2,323,705 7/1943Cooper 25l3l 2,971,237 2/1961 Graham 251l8 3,161,938 12/1964 Graham25-121 J. SPENCER OVERHOLSER, Primary Examiner.

WILLIAM J. STEPHENSON, Examiner.

1. A FASTENER FOR A FORM HAVING AN ELASTIC EDGE FOR MOLDING A THINCEMENTITIOUS PANEL HVING EMBEDDABLE REINFORCING STRAND MEANS; SAIDFASTENER CONSISTING OF A SINGLE METALLIC WIRE, SAID WIRE HAVING A LOWERLOOPED PORTION FORMING A BASE, SAID LOWER LOOPED PORTION FORMING ATLEAST ONE HOLE FOR RECEIVING A SUPPORTING ELEMENT, SAID WIRE HAVING ASUBSTANTIALLY VERTICAL PORTION AND AN UPPER LOOPED PORTION, SAID UPPERLOOPED PORTION FORMING AT LEAST ONE HOLE, SAID WIRE HAVING A PORTIONOFFSET FROM SAID VERTICAL PORTION, SAID OFFSET PORTION INCLUDING ATERMINAL PORTION OF SAID WIRE, SAID TERMINAL PORTION FORMING A PIN, SAIDPIN BEING SUBSTANTIALLY PARALLEL TO SAID VERTICAL PORTION SAID TERMINALPORTION PROJECTING OUTWARDLY AWAY FROM THE PLANE OF SAID BASE, EACH OFSAID EMBEDDABLE REINFORCING STRAND MEANS HAVING AN END PORTION WHICHINCLUDES AN APERTURE, SAID PIN ACCURATELY POSITIONING SAID STRAND MEANSEND PORTION SO THAT SAID APERTURE FACES TOWARDS THE PLANES OF THE MAJORSURFACES OF SAID PANEL, WHEREBY SAID STRAND MEANS END PORTION MAY BEQUICKLY COUPLED TO SAID PIN AND WHEREBY SAID PANEL MAY BE EASILY ANDQUICKLY PULLED AWAY FROM AND AUTOMATICALLY UNCOUPLED FROM SAID FASTENERWITHOUT DISTURBING SAID PIN.